Gov.Chris Christie receives the endorsement of Ray Pocino, vice-president of the Laborers' International Union of North America. Andrew Mills/Star-Ledger

What should we make of the super-early endorsement this week for Gov. Chris Christie from a laborers’ union?

For the governor, it is a timely flex of political muscle that could discourage a challenge from Newark Mayor Cory Booker or other top Democrats. For Ray Pocino, the head of the Laborers’ International Union of North America, the early move is shrewd. If this race goes according to script, a late endorsement won’t be worth much.

Pocino has reason to support the governor. Christie appointed him to a seat on the Port Authority board. And despite the tough talk on cutting costs, the governor has done nothing to challenge union control of public projects, or those subsidized with public money such as the Revel casino project.

But don’t misread this endorsement as anything more than mutual back-scratching. This does not mean that Christie is a friend of the working family, not by any stretch.

On the national front, Christie is a sturdy ally of Wisconsin Gov. Scott Walker, who essentially killed the right to collective bargaining for most public workers, and was a featured speaker at an event of the Koch brothers, among the leading financiers of the anti-union movement. He’s been a steadfast opponent of Obamacare.

In New Jersey, he has shown consistent bias against low-wage families. He has effectively raised taxes on the working poor by scaling back the earned income tax credit. He has made it harder for low-wage families to get subsidized health care, and says he may turn down federal money for an expansion of Medicaid eligibility. He raided more than $100 million from an affordable housing trust fund to help balance his budget.

He justified all that by saying the state government was broke and that we had to live within our means. And then he pressed relentlessly for income tax cuts tilted toward the rich. That is not how a friend of the working family behaves.

Pocino cited the governor’s management of the state economy, which was another odd twist. Christie is not to blame for the state’s high unemployment; he inherited a bad economy with a bloated public workforce.

Still, New Jersey’s economy is still lagging behind the nation’s three years after he swore his oath. He canceled the planned tunnel under the Hudson River, leaving $3 billion in federal money on the table, and still has found no way to fund transit projects. The state’s credit rating has dropped on his watch. How is that an admirable economic record?

Pocino’s endorsement, even before Democrats have picked a candidate, is testimony to the narrowing horizons of the modern labor movement. There was a day when union leaders felt common cause with all working families — not just those who pay dues.